The Rev Roll Ram is found in the Snowy Mountians of Pac-Man World 2. It can only be destroyed by Rev Rolling into it then Butt Bouncing on it. The Rev Roll Ram is usally found in herds so watch out. It will only roll in a straight line.
In Game Description
"High in the snowy mountains is where the Rev Roll Ram can be found. Be wary of its rolling attacks or you'll be knocked off the side of the mountain."